Lockable fuel cap

ABSTRACT

A lockable fuel cap is provided including a closure member having a drive tooth and a removal hub. The hub includes a drive lug and moves between a lock position in which the drive lug is spaced-apart from the drive tooth and a release position in which the drive lug engages the drive tooth. An outer shell is also provided and includes an interior wall defining a guiding slot to receive the drive lug and guide movement of the removal hub between the two positions. The shell is drivingly coupled to the hub so that the member remains stationary upon rotation of the shell when the drive lug is in the lock position. The member rotates upon rotation of the shell when the drive lug is in the release position.

This application is a continuation of provisional application Ser. No.60/044,501 filed Apr. 21, 1997.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a fuel cap that can be inserted into anopen end of a fuel tank filler neck, and particularly, to a fuel capthat can be locked after insertion into the filler neck to preventremoval of the fuel cap from the filler neck. More particularly, thepresent invention relates to a lockable fuel cap having a key-operatedlock cylinder that unlocks the fuel cap relative to the filler neck whena key is inserted into the lock cylinder and turned.

Fuel caps that couple to open ends of vehicle filler necks to close theopen end of the filler neck are known. See for example U.S. Pat. Nos.4,280,347 to Evans and 5,520,300 to Griffin. Some fuel caps havekey-operated locking mechanisms that are operable to lock the fuel capin the filler neck. During refueling of vehicles having key-operatedlocking mechanisms, a key is used to unlock the fuel cap allowing thefuel cap to be removed from the filler neck.

According to the present invention, a lockable fuel cap is provided formounting in an open end of a vehicle filler neck. The fuel cap includesa closure member adapted to mate with the open end of the vehicle fillerneck. The closure member is formed to include an interior region and adrive tooth positioned to lie in the interior region. The lockable fuelcap also includes a removal hub positioned to lie within the interiorregion of the closure member. The removal hub is formed to include adrive lug and is movable between a locking position in which the drivelug is spaced apart from the drive tooth of the closure member and areleasing position in which the drive lug engages the drive tooth. Thelockable fuel cap further includes an outer shell having an interiorwall. The interior wall of the outer shell defines a guide slot forreceiving the drive lug of the removal hub in order to guide themovement of the removal hub between the locking and releasing positions.The outer shell is also rotatable relative to the closure member whilebeing drivingly coupled to the removal hub so that the closure memberremains stationary upon rotation of the outer shell in a cap-removaldirection when the drive lug of the removal hub is in the lockingposition. Alternately, the closure member rotates in the cap-removaldirection upon rotation of the outer shell in the cap-removal directionwhen the drive lug is in the releasing position.

In preferred embodiments, the removal hub includes an arcuate front walland an arcuate rear wall. The arcuate front and rear walls are spacedapart such that an inner region is defined therebetween. The guide slotof the removal hub is formed in the front wall. The fuel cap of thepresent invention further comprises a lock cylinder rotatable relativeto the outer shell. The lock cylinder includes a throw member beingpositioned to lie within the inner region of the removal hub. Theremoval hub additionally includes a drive post such that during rotationof the lock cylinder to move the removal hub from the locking positionto the releasing position, the throw member engages the drive post.

Further, the lockable fuel cap includes an installation hub drivinglycoupled to the outer shell to transmit rotation of the outer shell in acap-installation direction to the closure member. The installation hubincludes a ring and a driven portion extending upwardly from the ringand into a cavity formed within the outer shell. The installation hubfurther includes flexible fingers appended to the ring and coupled to atorque-override ring that has radial drive teeth. The torque overridering is coupled to the closure member so that continued rotation of theouter shell in a cap installation direction after the closure member isadequately sealed within the filler neck, results in continued rotationof the installation hub and the torque-override ring without continuedrotation of the closure member.

Additional features and advantages of the present invention will becomeapparent to those skilled in the art upon consideration of the followingdetailed description of preferred embodiments exemplifying the best modeof carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is an exploded perspective view of a lockable fuel cap accordingto the present invention showing (from the top of the page to the bottomof the page) a lock cylinder and key, an outer shell having a raisedoperating handle and a portion broken away to expose a cylindricalinterior wall of the outer shell, an installation hub, a torque-overridering, a removal hub, an externally threaded closure member, and aretainer ring, and also showing a filler neck that receives the fuel cappositioned beneath the fuel cap;

FIG. 2 is a top plan view of the fuel cap of FIG. 1 (after assembly)showing the key inserted into the lock cylinder before it is turnedninety degrees (90°) in the direction of the double arrow from a firstposition (shown in solid) in which the fuel cap is locked to a secondposition (shown in phantom) in which the fuel cap is unlocked so thatthe fuel cap can be removed from the filler neck;

FIG. 3 is top plan view of the fuel cap of FIG. 2 after the key has beenturned ninety degrees(90°) to the second position;

FIG. 4 is a sectional view of the fuel cap and filler neck, taken alongline 4--4 of FIG. 2, showing the orientation of the key, the lockcylinder, and the removal hub when the fuel cap is he lock cylinderhaving a downwardly depending throw member engaging the removal hub;

FIG. 5 is a sectional view of the fuel cap, taken along line 5--5 ofFIG. 4, showing a cylindrical side wall of the closure member definingan interior region in the closure member, a plurality of drive teeth ofthe closure member appended to the cylindrical side wall and arranged toextend into the interior region, and the removal hub positioned to liein the interior region of the closure member, the removal hub includinga radially outwardly-extending lug that is closely adjacent to, butspaced apart from, one of the drive teeth;

FIG. 6 is a sectional view of the fuel cap and filler neck, taken alongline 6--6 of FIG. 3, showing the orientation of the key, the lockcylinder, and the removal hub after the key has been turned from thefirst position to the second position so that the throw member of thelock cylinder has been moved to shift the removal hub from the positionshown in FIG. 4 to the position shown in FIG. 6;

FIG. 7. is a sectional view taken along line 7--7 of FIG. 6, showing thelug of the removal hub engaging one of the teeth appended to the closuremember so that rotation of the removal hub in a counterclockwisecap-removal direction will result in rotation of the closure member inthe counterclockwise cap-removal direction;

FIG. 8 is an enlarged sectional view of a portion of the cylindricalinterior wall of the outer shell and a flexible finger of the removalhub showing the cylindrical interior wall including a snap rib and theflexible finger moving from a first position (in solid) in which theflexible finger engages a rear inclined edge of the rib to a secondposition (in phantom) in which the flexible finger engages a frontinclined edge of the rib;

FIG. 9 is a sectional view of the fuel cap and filler neck, taken alongline 9--9 of FIG. 3, showing the orientation of the fuel cap relative tothe filler neck after the cap has been rotated from the position shownin FIG. 6 one and a quarter turns in the counterclockwise cap-removaldirection;

FIG. 10 is a sectional view taken along line 10--10 of FIG. 9, withportions broken away, showing the driving connections between the outershell, the installation hub, the torque-override ring, and the closuremember that allow the fuel cap to be inserted into the filler neck, andshowing the driving connections between the outer shell, the removalhub, and the closure member that allow the fuel cap to be removed fromthe filler neck;

FIGS. 11-14 show a sequence wherein the removal hub is automaticallyreset to lock the fuel cap when the fuel cap is fully inserted into thefiller neck and the outer shell is further rotated in a clockwisecap-insertion direction to further rotate the removal hub in theclockwise cap-insertion direction;

FIG. 11 is a view similar to FIG. 7 showing the removal hub at aposition in which a ramp surface of the lug of the removal hub isengaging a ramp surface of one of the plurality of teeth of the closuremember;

FIG. 12 is a view similar to FIG. 11 showing the removal hub shiftingrelative to the cylindrical interior wall of the outer shell in thedirection of the single arrow in response to further rotation of theremoval hub in the cap-insertion direction;

FIG. 13 is an enlarged sectional view of a portion of the cylindricalinterior wall of the outer shell and one of the flexible fingers of theremoval hub showing the flexible finger moving from a transitionposition (in solid) in which an apex of the flexible finger engages anapex of the snap rib, back to the first position (in phantom) in whichthe flexible finger engages the rear inclined edge of the snap rib; and

FIG. 14 is a view similar to FIG. 12 showing the removal hub moved to aposition in which the lug of the removal hub is separated away from theteeth of the closure member so that the closure member does not rotatein response to rotation of the removal hub in the cap-removal direction.

DETAILED DESCRIPTION OF THE DRAWINGS

An exploded view of a lockable fuel cap 20 in accordance with thepresent invention is shown in FIG. 1. Fuel cap 20 includes an outershell 22, an installation hub 24, a torque-override ring 26, a removalhub 28, an externally threaded closure member 30, and a retainer ring32. Fuel cap 20 also includes a lock cylinder 34 that is operated by akey 36. Outer shell 22 is formed to include a cylindrical interior wall38 having a bore 40 into which lock cylinder 34 is inserted. Fuel cap 20can be threaded into an open end 42 of a fuel tank filler neck 44 sothat an O-ring 46 mounted on closure member 30 seals against a lip 48 offiller neck 44 to close off open end 42 of filler neck 44.

Outer shell 22 of fuel cap 20 includes a raised operating handle 50 thatextends diametrically across outer shell 22 as shown in FIGS. 1-3.Operating handle 50 can be grasped to rotate fuel cap 20 relative tofiller neck 44 during installation of fuel cap 20 into filler neck 44and during removal of fuel cap 20 from filler neck 44.

Fuel cap 20 can be locked to prevent removal of fuel cap 20 from fillerneck 44 when installed therein. Fuel cap 20 can also be unlocked toallow removal of fuel cap 20 from filler neck 44. When fuel cap 20 islocked, outer shell 22 can be rotated in a counterclockwise cap-removaldirection, indicated by arrow 54 shown in FIGS. 1 and 2, but closuremember 30 will remain stationary relative to filler neck 44 so that fuelcap 20 remains installed in filler neck 44. When fuel cap 20 isunlocked, rotation of outer shell 22 in cap-removal direction 54 resultsin rotation of closure member 30 in cap-removal direction 54 relative tofiller neck 44 so that fuel cap 20 can be removed from filler neck 44.

Key 36 can be inserted into lock cylinder 34 and turned in a directionindicated by arrow 52, shown in FIG. 2, from a first position, shown inFIG. 2 (in solid), to a second position, shown in FIGS. 2 and 3 (inphantom in FIG. 2). When key 36 is in the second position, fuel cap 20is unlocked and can be removed from filler neck 44. During the removalof fuel cap 20 from filler neck 44, key 36 can be left in lock cylinder34 in the second position, shown in FIG. 3, or key 36 can be rotatedback to the first position, shown in FIG. 2, and either left in lockcylinder 34 in the first position or removed from lock cylinder 34altogether. Thus, once key 36 has been rotated in direction 52 from thefirst position to the second position to unlock fuel cap 20, fuel cap 20remains unlocked during the removal of fuel cap 20 from filler neck 44regardless of the position of key 36 and regardless of whether key 36remains inserted in lock cylinder 34.

After fuel cap 20 has been removed from filler neck 44, thereby allowingthe vehicle (not shown) associated with filler neck 44 to be refueled,fuel cap 20 can be installed back into filler neck 44 by rotation ofouter shell 22 in a clockwise cap-installing direction, as indicated byarrow 56 shown in FIGS. 1 and 3 (in phantom). Rotation of outer shell 22in cap-installing direction 56 results in rotation of closure member 30in cap-installing direction 56 relative to filler neck 44 until O-ring46 seals against lip 48 of filler neck 44. When O-ring 46 seals againstlip 48, closure member 30 can no longer rotate in cap-installingdirection 56 relative to filler neck 44.

A torque override connection between outer shell 22 and closure member30 allows outer shell 22 to be further rotated in cap-installingdirection 56 after O-ring 46 seals against lip 48 of filler neck 44.During installation of fuel cap 20 back into filler neck 44, after fuelcap 20 has been unlocked and removed from filler neck 44, fuel cap 20remains unlocked while outer shell 22 and closure member 30 are rotatedin cap-installing direction 56. After O-ring 46 seals against lip 48 offiller neck 44, fuel cap 20 automatically locks when outer shell 22 isrotated by a slight amount in cap-installing direction 56 relative toclosure member 30.

The various components of fuel cap 20 cooperate to establish and disableseparate driving connections for cap removal and installation. Twoseparate driving connections permit installation and removal of fuel cap20 from filler neck 44. In a first cap-installing driving connection,outer shell 22 is drivingly coupled to installation hub 24, installationhub 24 is drivingly coupled to torque-override ring 26, andtorque-override ring 26 is drivingly coupled to closure member 30.Rotation of outer shell 22 in cap-installing direction 56 is transmittedto closure member 30 through installation hub 24 and torque-overridering 26.

In a second cap-removing driving connection, which is only establishedwhen fuel cap 20 is unlocked, outer shell 22 is drivingly coupled toremoval hub 28 and removal hub 28 is drivingly coupled to closure member30 so that rotation of outer shell 22 in cap-removal direction 54 istransmitted to closure member 30 through removal hub 28. When fuel cap20 is locked, outer shell 22 is still drivingly connected to removal hub28 but removal hub 28 is no longer drivingly coupled to closure member30. Thus, whether removal hub 28 is drivingly coupled to closure member30 determines whether fuel cap 20 is locked or unlocked.

Removal hub 28 includes an arcuate front wall 58 and an arcuate rearwall 60 spaced apart from front wall 58 to define an interior region 62therebetween as shown in FIG. 1. Rear wall 60 includes an inner surface64 and a first guide lug 66 extends forwardly away from inner surface 64into interior region 62. Front wall 58 includes an inner surface 68 andan outer surface 70. A second guide lug 72 extends rearwardly away frominner surface 68 toward first guide lug 66 and a drive lug 74 extendsforwardly away from outer surface 70. A drive post 76 of removal hub 28is positioned to lie in interior region 62 between front and rear walls58, 60. Second guide lug 72 connects front wall 58 to drive post 76.

Cylindrical interior wall 38 of outer shell 22 is formed to include afirst guide slot 78 that receives first guide lug 66 and a second guideslot 80 that receives second guide lug 72. When first and second guidelugs 66, 72 are received in respective first and second guide slots 78,80, an upper portion of drive post 76 of removal hub 28 is received inbore 40 of cylindrical interior wall 38 and a lower portion ofcylindrical interior wall 38 is received in interior region 62 ofremoval hub 28. In addition, cylindrical interior wall 38 engages firstand second guide lugs 66, 72 to establish the driving connection betweenouter shell 22 and removal hub 28 so that rotation of outer shell 22results in rotation of removal hub 28.

Closure member 30 includes a cylindrical side wall 82 defining aninterior region 84 that receives removal hub 28. Closure member 30 alsoincludes a plurality of axially-extending drive teeth 86 extending awayfrom side wall 82 into interior region 84. In addition, closure member30 includes an external thread 88 appended to side wall 82. Thread 88 isadapted to be received by a spiral groove 90 formed in filler neck 44adjacent to lip 48 to threadably couple fuel cap 20 to filler neck 44.Closure member 30 further includes an annular flange 92 extendingradially away from side wall 82 in perpendicular relation therewith.

Closure member 30 includes a valve housing structure 94 appended to sidewall 82 beneath axially-extending drive teeth 86 of closure member 30 asshown in FIGS. 4, 6, and 9. Fuel cap 20 includes a vent valve assembly96 carried by valve housing structure 94 within interior region 84 ofclosure member 30. Vent valve assembly 96 operates in a conventionalmanner to allow excess pressure to vent out of filler neck 44 and toallow ambient air to vent into filler neck 44. The operation of ventvalve assembly 96 is unrelated to the locking and unlocking of fuel cap20. Valve housing structure 94 includes a plurality of tabs 98 thatengage vent valve assembly 96 to secure vent valve assembly 96 withinvalve housing structure 94.

Removal hub 28 is supported within interior region 84 of closure member30 by tabs 98 of valve housing structure 94. Tabs 98 engage a bottomplate 100 of removal hub 28 as shown in FIGS. 4, 6, and 9. Removal hub28 can be shifted within interior region 84 of closure member 30 betweena rearward locking position in which drive lug 74 is spaced apart fromdrive teeth 86, as shown in FIGS. 4 and 5, and a forward unlockingposition in which drive lug 74 can engage one of drive teeth 86, asshown in FIGS. 6 and 7. First and second guide slots 78, 80 formed incylindrical interior wall 38 cooperate with first and second guide lugs66, 72 of removal hub to define a diametral shift path 110, shown inFIG. 5 (dotted line), along which removal hub 28 moves when shiftedbetween the locking and unlocking positions relative to closure member30.

As previously described, lock cylinder 34 is inserted into bore 40formed in cylindrical interior wall 38 of outer shell 22. Lock cylinder34 includes a throw member 112 and drive post 76 is formed to include acut-out 114 that receives throw member 112. Drive post 76 includes afirst surface 116 and a drive surface 118 that cooperates with firstsurface 116 to define cut-out 114. When key 36 is inserted into lockcylinder 34 and turned in direction 52 from the locking position to theunlocking position, throw member 112 engages drive surface 118 to pushremoval hub 28 along shift path 110 from the locking position, shown inFIGS. 4 and 5, to the unlocking position, shown in FIGS. 6 and 7.

Drive lug 74 of removal hub 28 includes a drive surface 120 and eachaxially-extending drive tooth 86 includes a drive surface 122 as shownin FIG. 5. Rotation of outer shell 22 in cap-removal direction 54, afterremoval hub 28 has been shifted to the unlocking position, causes drivesurface 120 of drive lug 74 to engage drive surface 122 of one of driveteeth 86. Further rotation of outer shell 22 in cap-removal direction54, after drive surface 120 engages one of drive surfaces 122, causesclosure member 30 to rotate in cap-removal direction 54 relative tofiller neck 44. As outer shell 22 and closure member 30 are rotated incap-removal direction 54, O-ring 46 separates away from lip 48 of fillerneck 44, as shown, for example, in FIG. 9. After sufficient rotation ofouter shell 22 and closure member 30 in cap-removal direction 54, fuelcap 20 can be completely removed from filler neck 44.

Removal hub 28 includes a pair of spaced-apart flexible fingers 124 asshown in FIG. 1. Each finger 124 is L-shaped and includes a firstportion appended to front wall 58 and extending rearwardly therefromtoward rear wall 60 into a respective gap 126 formed between front andrear walls 58, 60. Each finger 124 also includes a second portion thatis perpendicular to the first portion and extends into interior region62 toward drive post 76. The second portion of each flexible finger 124includes a front ramp edge 128 and a rear ramp edge 130 as shown, forexample, in FIG. 7.

Cylindrical interior wall 38 of outer shell 22 is formed to include apair of axially-extending snap ribs 132 as shown, for example, in FIG.5. Each snap rib 132 includes a front inclined edge 134 and rearinclined edge 136. As removal hub 28 is moved along shift path 110 fromthe locking position to the unlocking position in response to actuationof throw member 112 by rotation of key 36 in direction 52, flexiblefingers 124 move from a first position, shown in FIGS. 5 and 8, in whichfront ramp edge 128 of each finger 124 engages rear inclined edge 136 ofthe companion snap rib 132, to a second position, shown in FIG. 7, inwhich rear ramp edge 130 of each finger 124 faces toward front inclinededge 134 of the companion snap rib 132.

Fingers 124 are resiliently deflected outwardly away from one another asa result of each front ramp edge 128 camming against the companion rearinclined edge 136 during initial forward movement of removal hub 28 fromthe locking position toward the unlocking position. Each finger 124 isat its maximum deflection when the apex formed at the junction of frontand rear ramp edges 128, 130 of the respective finger 124 engages theapex formed at the junction of the companion front and rear inclinededges 134, 136 of the respective snap rib 132, as shown, for example, inFIG. 13. Fingers 124 resiliently deflect inwardly toward one another andeach rear ramp edge 130 cams against the companion front inclined edge134 during further forward movement of removal hub 28 from the lockingposition toward the unlocking position as shown in FIG. 8 (in phantom).Thus, each flexible finger 124 snaps over the companion snap rib 132 asremoval hub 28 is driven from the locking position to the unlockingposition by throw member 112.

When removal hub 28 is in the unlocking position, fingers 124 cooperatewith snap ribs 132 to prevent removal hub 28 from inadvertently shiftingback into the locking position. Thus, after key 36 has been turned indirection 52 to the second position, shown in FIG. 3, having throwmember 112 in a position engaging drive surface 118 of drive post 76 asshown in FIG. 7, key 36 can be turned back to the first position, shownin FIG. 2, which moves throw member 112 into a disengaged position shownin FIG. 7 (in phantom), and removal hub 28 will remain in the unlockingposition. Movement of removal hub 28 back into the locking position isdiscussed below with reference to FIGS. 11-14.

Lock cylinder 34 includes a circumferential retainer groove 138, shownin FIG. 1, and outer shell 22 includes a pair of arcuate retaining teeth140, shown in FIG. 9, appended to cylindrical interior wall 38 andextending into retainer groove 138 to retain lock cylinder 34 in bore 40of interior wall 38. Lock cylinder 34 also includes a positioning lug142. Cylindrical interior wall 38 is formed to include an arcuate groove144, shown in FIG. 3 (in phantom), that receives positioning lug 142.

Positioning lug 142 slides relative to outer shell 22 within groove 144as lock cylinder 34 is rotated between the first position, shown in FIG.2, and the second position, shown in FIG. 3. Ends of groove 144 aredefined by first and second stop surfaces 146, 148 as shown in FIG. 3.Engagement of lug 142 with first and second stop surfaces 146, 148limits the amount by which lock cylinder 34 can rotate relative to outershell 22. Groove 144 and lug 142 are formed so that lock cylinder 34 canrotate through an angle of ninety degrees (90°) when moved between thefirst and second positions.

A plurality of locking plates 150 are spring-biased out of associatedslots 152 formed in lock cylinder 34 and cylindrical interior wall 34 isformed to include an axially-extending channel 154 that receives plates150 when lock cylinder 34 is in the first position. Insertion of key 36into lock cylinder 34 retracts locking plates 150 into lock cylinder 34,thereby moving locking plates 150 out of channel 154. When lockingplates 150 are retracted, lock cylinder 34 is unlocked from outer shell22 and can rotate relative to cylindrical interior wall 38 in responseto rotation of key 36.

When lock cylinder 34 is rotated out of the first position, key 36cannot be removed from lock cylinder 34 so that locking plates 150remain retracted into lock cylinder 34. Key 36 can only be removed fromlock cylinder 34 when lock cylinder 34 is in the first position havinglocking plates 150 aligned with channel 154. When key 36 is removed fromlock cylinder 34, locking plates 150 are spring-biased into channel 154.Receipt of locking plates 150 in channel 154 automatically locks lockcylinder 34, thereby preventing lock cylinder 34 from rotating relativeto outer shell 22.

After fuel cap 20 is unlocked and removed from filler neck 44, thevehicle associated with filler neck 44 can be refueled through fillerneck 44 in a conventional manner. After the vehicle is refueled, fuelcap 20 can be installed back into filler neck 44. As previouslydescribed, outer shell 22 is drivingly coupled to installation hub 24,installation hub 24 is drivingly coupled to torque-override ring 26, andtorque-override ring 26 is drivingly coupled to closure member 30 sothat rotation of outer shell 22 in cap-installing direction 56 allowsfuel cap 20 to be installed in filler neck 44.

Outer shell 22 includes a circular top plate 156 and a cylindrical outerwall 158 that extends downwardly from a perimeter 160 of top plate 156as shown in FIG. 1.

Operating handle 50 extends upwardly from top plate 156. Operatinghandle 50 includes a flat top portion 162 at the center of outer shell22 and opposing angled side portions 164 that slope from top portion 162down to perimeter 160 of top plate 156. Side portions 164 of operatinghandle 50 are each formed to include a cavity 166.

Cylindrical interior wall 38 of outer shell 22 extends downwardly fromtop portion 162 of operating handle 50 past top plate 156 as shown inFIGS. 1 and 9. Outer shell 22 is formed so that a bottom edge 163 ofcylindrical interior wall 38 is spaced apart from top plate 156 by anamount that is approximately the same as the amount by which a bottomedge 165 of cylindrical outer wall 158 is spaced apart from top plate156.

Cylindrical outer wall 158 of outer shell 22 is formed to include aplurality of circumferentially-spaced inwardly-directed teeth 168 asshown, for example, in FIGS. 1 and 4. Annular flange 92 of closuremember 30 has an outer perimetral lip 170. Annular flange 92 isappropriately sized to allow closure member 30 to mate with outer shell22 so that perimetral lip 170 is closely adjacent to cylindrical outerwall 158 as shown in FIG. 4.

Retainer ring 32 includes a perimetral skirt 172 that engages teeth 168to retain retainer ring 32 inside outer shell 22. Outer shell 22 isformed to include a plurality of generally rectangular piloting webs 174at the corner formed by outer wall 158 and top plate 156 and perimetrallip 170 is positioned to lie between piloting webs 174 and retainer ring32. Thus, perimetral lip 170 of annular flange 92 is trapped betweenpiloting webs 174 and retainer ring 32, thereby preventing separation ofclosure member 30 from outer shell 22.

Piloting webs 174 ensure that annular flange 92 is axially spaced apartfrom top plate 156 of outer shell 22 by a sufficient distance to allowtorque-override ring 26 to be sandwiched between annular flange 92 andtop plate 156 as shown in FIGS. 4, 6, and 9. Torque-override ring 26includes an annular disk portion 176 which is formed to include a largeaperture 178 as shown in FIG. 1. Torque-override ring 26 also includes aplurality of radial drive teeth 180 extending radially away from diskportion 176 into aperture 178 and a plurality of axial drive teeth 182extending axially away from disk portion 176 toward annular flange 92 ofclosure member 30.

Annular flange 92 of closure member 30 is formed to include a pluralityof generally rectangular apertures 184 as shown in FIG. 1. A flexiblefinger 186 extends into each of apertures 184 and an upwardly-extendingdrive tooth 188 is appended to the end of each finger 186.Torque-override ring 26 rests upon annular flange 92 of closure member30 so that axial drive teeth 182 of torque-override ring 26 interactwith drive teeth 188. Piloting webs 174 and top plate 156 of outer shell22 cooperate to orient torque-override ring 26 at the proper positionrelative to closure member 30 to maintain engagement between axial driveteeth 182 and drive teeth 188.

Installation hub 24 is also sandwiched between annular flange 92 ofclosure member 30 and outer shell 22. Installation hub 24 includes aring 190, a pair of driven portions 192 extending upwardly from ring190, and a pair of curved flexible arms 194 attached to and extendingalongside ring 190 as shown in FIG. 1. A drive tooth 196 is appended tothe end of each flexible arm 194.

Each of driven portions 192 are received by respective cavities 166formed in operating handle 50 so that angled side portions 164 engagedriven portions 192 as shown in FIGS. 9 and 10. Engagement of sideportions 164 of operating handle 50 with driven portions 192 ofinstallation hub 24 establishes the driving connection between outershell 22 and installation hub 24. Thus, installation hub 24 rotatesalong with outer shell 22 when outer shell 22 is rotated in eithercap-removal direction 54 or cap-installing direction 56.

Ring 190 and flexible arms 194 of installation hub 24 are positioned tolie between annular flange 92 of closure member 30 and top plate 156 ofouter shell 22 as shown, for example, in FIG. 4, so that the amount bywhich installation hub 24 can axially move is limited. In addition,outer shell 22 is formed to include a pair of downwardly-extendingarcuate locating ribs 198, shown best in FIG. 1, that are received by anaperture 200 formed in ring 190 of installation hub 24 so that theamount by which installation hub 24 can radially move is limited.Closure member 30 and outer shell 22 cooperate to position installationhub 24 within aperture 178 formed in disk portion 176 of torque-overridering 26 so that drive teeth 196 appended to flexible arms 194 ofinstallation hub 24 can interact with radial drive teeth 180 oftorque-override ring 26.

When outer shell 22 is rotated in cap-installing direction 56,installation hub 24 rotates along with outer shell 22 due to the drivingconnection between angled side porions 164 of operating handle 50 anddriven portions 192 of installation hub 24. Rotation of installation hub24 in cap-installing direction 56 causes a drive surface 210 of eachdrive tooth 196 appended to each respective flexible arm 194 todrivingly engage a drive surface 212 of two of radial drive teeth 180appended to torque-override ring 26 as shown in FIG. 10. Engagement ofdrive surfaces 210 with respective drive surfaces 212 causestorque-override ring 26 to rotate in cap-installing direction 56 alongwith installation hub 24 and outer shell 22.

Rotation of torque-override ring 26 in cap-installing direction 56during installation of fuel cap 20 in filler neck 44, causes a rampsurface 214 of selected axial drive teeth 182 appended to disk portion176 of torque-override ring 26 to engage a corresponding ramp surface216 of drive teeth 188 appended to closure member 30 so that closuremember 30 also rotates in cap-installing direction 56 along withinstallation hub 24, outer shell 22, and torque-override ring 26.Flexible arms 194 have sufficient stiffness to sustain the drivingconnection between teeth 182 appended to torque-override ring 26 andteeth 188 appended to closure member 30 until O-ring 46 seats againstlip 48 of filler neck 44. Closure member 30 stops rotating incap-installing direction 56 once O-ring 46 is adequately seated againstlip 48 of filler neck 44.

Continued rotation of outer shell 22 in cap-installing direction 56after O-ring 46 is adequately seated against lip 48 of filler neck 44,results in continued rotation of installation hub 24 and torque-overridering 26 in cap-installing direction 56. However, closure member 30 willbe constrained from rotating in cap-installing direction 56 due toseating of O-ring 48 against lip 48 of filler neck 44 and ramp surfaces214 of axial drive teeth will cam against ramp surfaces 216 of driveteeth 188, thereby deflecting flexible fingers 186 away fromtorque-override ring 26 so that teeth 180 can move past teeth 188. Thus,flexible fingers 186 ratchet within apertures 184 relative totorque-override ring 26 to provide the torque override connectionbetween outer shell 22 and closure member 30.

As previously described, fuel cap 20 remains unlocked while outer shell22 and closure member 30 are rotated in cap-installing direction 56during installation of fuel cap 20 back into filler neck 44. As alsopreviously described, fuel cap 20 automatically locks when outer shell22 is rotated by a slight amount in cap-installing direction 56 relativeto closure member 30 after O-ring 46 seats against lip 48 of filler neck44.

When outer shell 22, installation hub 24, and torque-override ring 26are rotated in cap-installing direction 56 after O-ring 46 is seatedagainst lip 48 of filler neck 44, removal hub 28 also rotates incap-installing direction 56 due to the driving connection betweencylindrical outer wall 38 of outer shell 22 and first and second guidelugs 66, 72 of removal hub 28. Rotation of removal hub 28 incap-installing direction 56, causes a ramp surface 218 of drive lug 74to engage a ramp surface 220 of one of axially-extending drive teeth 86as shown in FIG. 11.

Continued rotation of outer shell 22 in cap-installing direction 56after ramp surface 218 engages one of ramp surfaces 220, results inmovement of removal hub 28 relative to cylindrical interior wall 38 ofouter shell 22 along shift path 110 in a direction indicated by arrow222 shown in FIG. 12. Further rotation of outer shell 22 incap-installing direction 56 after ramp surface 218 engages one of rampsurfaces 220, results in removal 28 being returned to the lockingposition as shown in FIG. 14. Thus, rotation of outer shell 22 incap-removal direction 56 relative to closure member 30 automaticallylocks fuel cap 20 due to movement of removal hub 28 into the lockingposition in response to camming engagement between ramp surface 218 ofdrive lug 74 and ramp surface 220 of one of drive teeth 86.

As removal hub 28 moves along shift path 110 toward the locking positionin response to camming engagement between ramp surface 218 and rampsurface 220, flexible fingers 124 deflect from the position shown inFIG. 11, in which rear ramp edge 130 of each finger 124 faces towardfront inclined edge 134 of the companion snap rib 132, through theposition shown in FIG. 12, in which fingers 124 are at their maximumdeflection orientations, and then into the position shown in FIG. 14, inwhich front ramp edge 128 of each finger 124 engages rear inclined edge136 of the companion snap rib 132. Thus, each flexible finger 124 snapsover the companion snap rib 132 as removal hub 28 is driven back intothe locking position.

If lock cylinder 34 is at the second position having throw member 112engaging drive surface 118 of drive post 76, when removal hub 28 ismoved from the position shown in FIG. 11 to the position shown in FIG.14, drive surface 118 will engage throw member 112 to automaticallyrotate lock cylinder 34 relative to outer shell 22 from the secondposition, shown in FIG. 3, back to the first position, shown in FIG. 2.In addition, during automatic movement of lock cylinder 34 from thesecond position back to the first position, key 36 will rotate alongwith lock cylinder 34.

When removal hub 28 is in the locking position, fingers 124 cooperatewith snap ribs 132 to prevent removal hub 28 from inadvertently shiftinginto the unlocking position. Thus, removal hub 28 will remain in thelocking position until key 36 is, once again, inserted into lockcylinder and turned in direction 52 to unlock fuel cap 20.

If outer shell 22 is rotated in cap-removal direction 54 when removalhub 28 is in the locking position having drive lug 74 disengaged fromclosure member 30, removal hub 28 will rotate within interior region 84of closure member 30 in cap-removal direction 54 without any resultingrotation of closure member 30 in cap-removal direction 54. As removalhub 28 rotates within interior region 84 of closure member 30 incap-removal direction 54 relative to closure member 30, installation hub24 also rotates in cap-removal direction 54 due to the drivingconnection between driven portions 192 and angled side portions 164 ofoperating handle 50.

Rotation of installation hub 24 in cap-removal direction 54 causes aramp surface 224 of each drive tooth 196 to engage a ramp surface 226 ofrespective radial drive teeth 180. The rotational torque imparted onclosure member 30 by installation hub 24 through torque-override ring 26as a result of the engagement of ramp surface 224 with ramp surface 226is insufficient to cause closure member 30 to rotate in cap-removaldirection 54 relative to filler neck 44. Thus, engagement of rampsurfaces 224 of teeth 196 with ramp surfaces 226 of teeth 180 asinstallation hub 24 is rotated in cap-removal direction 54 results inflexible arms 194 bending inwardly toward ring 190 of installation hub24 so that teeth 196 can move past teeth 180 rather than resulting inrotation of closure member 30 relative to filler neck 44.

Although the invention has been described in detail with reference to acertain preferred embodiment, variations and modifications exist withinthe scope and spirit of the invention as described and defined in thefollowing claims.

What is claimed is:
 1. A lockable fuel cap for mounting in an open endof a vehicle filler neck, the fuel cap comprisinga closure memberadapted to mate with the open end of the vehicle filler neck, theclosure member being formed to include an interior region and having adrive tooth positioned to lie in the interior region, a removal hubpositioned to lie in the interior region of the closure member and beingformed to include a drive lug, the removal hub being movable between alocking position in which the drive lug is spaced apart from the drivetooth and a releasing position in which the drive lug engages the drivetooth, and an outer shell including an interior wall defining a guideslot receiving the drive lug and guiding the movement of the removal hubbetween the locking and releasing positions, the outer shell beingrotatable relative to the closure member and drivingly coupled to theremoval hub so that the closure member remains generally stationary uponrotation of the outer shell in a cap-removal direction when the drivelug is in the locking position and the closure member rotates in thecap-removal direction upon rotation of the outer shell in thecap-removal direction when the drive lug is in the releasing position.2. The fuel cap of claim 1, wherein the removal hub includes an arcuatefront wall and an arcuate rear wall spaced apart from the arcuate frontwall to define an inner region therebetween and the drive lug is coupledto the front wall.
 3. The fuel cap of claim 2, further comprising a lockcylinder rotatable relative to the outer shell, the lock cylinderincluding a throw member positioned to lie within the inner region ofthe removal hub.
 4. The fuel cap of claim 3, wherein the removal hubincludes a drive post and the throw member selectively engages the drivepost during rotation of the lock cylinder in the cap-removal directionto move the removal hub from the locking position to the releasingposition.
 5. The fuel cap of claim 4, wherein the removal hub includes apair of fingers appended to one of the arcuate front and rear walls, theinterior wall of the outer shell is formed to include a pair of ribs,and each finger moves across a respective rib during movement of theremoval hub between the locking position and the releasing position. 6.The fuel cap of claim 5, wherein the fingers are flexible and deflectaway from the interior wall of the outer shell upon movement of thefingers across the respective rib.
 7. The fuel cap of claim 2, whereinthe interior wall is formed to include a second guide slot, the drivelug includes a first guide lug received by the guide slot for slidingmovement relative to the interior wall and the removal hub includes asecond guide lug received by the second slot for sliding movementrelative to the interior wall.
 8. The fuel cap of claim 7, furthercomprising a lock cylinder rotatable relative to the outer shell, thelock cylinder including a throw member positioned to lie within theinner region of the removal hub.
 9. The fuel cap of claim 8, wherein theremoval hub includes a drive post positioned to lie between the firstand second guide lugs and the throw member selectively engages the drivepost during rotation of the lock cylinder to move the removal hub fromthe locking position to the releasing position.
 10. The fuel cap ofclaim 1, wherein the outer shell includes a top plate positioned to lieoutside the interior region of the closure member and an outer wallappended to the top plate and extending over the closure member.
 11. Thefuel cap of claim 10, wherein the outer wall includes a first bottomedge spaced a first distance from the top plate and the interior wallincludes a second bottom edge spaced a second distance from the topplate and the first distance is substantially equal to the seconddistance.
 12. The fuel cap of claim 1, wherein the interior wall of theouter shell is formed to include an axial rib and the removal hub isformed to include a finger that deflects to snap over the rib as theremoval hub moves between the locking and releasing positions.
 13. Thefuel cap of claim 12, wherein the interior wall is formed to include asecond guide slot, the drive lug includes a first guide lug received bythe guide slot for sliding movement relative to the interior wall andthe removal hub includes a second guide lug received by the second slotfor sliding movement relative to the interior wall.
 14. The fuel cap ofclaim 13, wherein the finger is positioned to lie between the first andsecond guide lugs.
 15. The fuel cap of claim 1, further comprising aninstallation hub drivingly coupled to outer shell to transmit rotationof the outer shell in a cap-installation direction to closure.
 16. Thefuel cap of claim 15, wherein the outer shell includes a top platepositioned to lie outside the interior region of the closure member anda handle extending from the top plate and the handle engages the drivenportion of the installation hub.
 17. The fuel cap of claim 15, whereinthe installation hub includes a ring and a driven portion extendingupwardly from the ring.
 18. The fuel cap of claim 17, wherein the fuelcap further includes a torque-override ring drivingly coupled to boththe installation hub and the closure member such that rotation of theouter shell in the cap-installation direction is transmitted to theclosure through the installation hub and torque-override ring.
 19. Thefuel cap of claim 17, further comprising a torque-override ringdrivingly coupled to the installation hub and the closure member totransfer rotational movement of the outer shell from the installationhub to the closure member in the cap-installation direction.
 20. Thefuel cap of claim 19, wherein the torque-override ring forms radialdrive teeth and axial drive teeth, the installation hub includesflexible arms, and the closure member includes upwardly extending teethso that the radial drive teeth of the torque-override ring engage theflexible arms and the axial drive teeth engage the upwardly extendingteeth of the closure member during rotation of the outer shell in thecap-installation direction.
 21. The fuel cap of claim 20, wherein theteeth of the closure member, the radial and axial drive teeth of thetorque-override ring, and the flexible fingers include cammed surfaces.22. The fuel cap of claim 20, wherein the drive tooth of the closuremember is formed to include a first drive edge and a first ramp edge,the drive lug of the removal hub includes a second drive edge and asecond ramp edge, the first drive edge engages the second drive edgewhen the outer shell is rotated in the cap-removal direction, and thefirst ramp edge engages the second ramp edge to move the removal hubfrom the releasing position to the locking position during movement ofthe outer shell in a cap-removal direction after the closure member isseated against the filler neck.
 23. The fuel cap of claim 15, whereinthe installation hub includes a ring with flexible fingers extendingfrom the ring, the closure member includes an outer lip and teethextending upward from the outer lip, the torque-override ring includesradial drive teeth and axial drive teeth such that the radial driveteeth engage the flexible fingers and the axial drive teeth engage theteeth of the closure member during rotation of the outer shell in thecap-installation direction.
 24. A lockable fuel cap for mounting in anopen end of a vehicle filler neck, the fuel cap comprisinga closuremember adapted to mate with the open end of the vehicle filler neck, theclosure member being formed to include an interior region and having adrive tooth positioned to lie in the interior region, an outer shellbeing rotatable relative to the closure member, the outer shellincluding an interior wall being positioned to extend into the interiorregion of the closure member, a removal hub drivingly coupled to theinterior wall of the closure member, the removal hub including a drivelug and being formed for movement between a locking position in whichthe drive lug is spaced apart from the drive tooth of the closure memberso that the closure member remains generally stationary when the outershell is rotated in a cap-removal direction and a releasing position inwhich the drive lug engages the drive tooth so that rotation of theouter shell in the cap-removal direction rotates the removal hub and theclosure member in the cap-removal direction, and a lock core coupled tothe outer shell, the lock core being rotatable relative to the outershell and including a throw member positioned to lie in the interiorregion of the closure member, rotation of the lock core moving the throwmember into engagement with the removal hub to move the removal hub fromthe locking position to the releasing position.
 25. The fuel cap ofclaim 24, wherein the interior wall is formed to include a slot and theremoval hub is formed to include a guide lug such that the guide lug isreceived in the slot to guide the movement of the removal hub betweenlocking and releasing positions.
 26. The fuel cap of claim 25, whereinthe interior wall is further formed to include a pair of ribs and theremoval hub is formed to include a pair of fingers that snap over theribs as the removal hub moves between locking and releasing positions.27. The fuel cap of claim 26, wherein the interior wall is cylindrical,the slot is formed so that the removal hub is movable relative to theinterior wall along a first diameter of the interior wall, and the pairof ribs of the interior wall are positioned to lie along a seconddiameter of the interior wall that is generally orthogonal to the firstdiameter.
 28. The fuel cap of claim 24, wherein the removal hub isformed to include a front arcuate wall, a rear arcuate wall, and aninner space defined between front and rear arcuate walls, the interiorwall of the outer shell includes a portion that is positioned to lie inthe inner space, and the throw member is positioned to lie in the innerspace.
 29. The fuel cap of claim 28, wherein the interior wall is formedto include an edge defining a slot and the removal hub includes asurface that slides relative to the edge during movement of the removalhub between locking and releasing positions.
 30. The fuel cap of claim29, wherein the removal hub includes a drive post selectively engaged bythe throw member to move the removal hub from the locking position tothe releasing position and a guide lug extending between the drive lugand the drive post, the guide lug provides the surface that slidesrelative to the edge, and the edge is positioned to lie between thedrive lug and the drive post.
 31. The fuel cap of claim 24, wherein theremoval hub is formed to include a drive post, the drive post is formedto include a cut-out bounded by a drive surface, the throw member ispositioned to lie in the cut-out, and the throw member engages the drivesurface as the lock core is rotated to move the removal hub from thelocking position to the releasing position.
 32. The fuel cap of claim31, wherein the interior wall is formed to include a bore and a portionof the drive post is positioned to lie in the bore.
 33. The fuel cap ofclaim 24, wherein the drive tooth of the closure member is formed toinclude a first drive edge and a first ramp edge, the drive lug of theremoval hub includes a second drive edge and a second ramp edge, thefirst drive edge engages the second drive edge when the outer shell isrotated in the cap-removal direction, the first ramp edge engages thesecond ramp edge to move the removal hub from the releasing position tothe locking position during movement of the outer shell in a cap-removaldirection after the closure member is seated against the filler neck.34. The fuel cap of claim 24, wherein the interior wall is formed toinclude first and second slots, the removal hub includes a first guidelug received by the first slot and a second guide lug received by thesecond slot, and the removal hub is further formed to include a drivepost that is positioned to lie between the first and second guide lugs.35. The fuel cap of claim 34, wherein the removal hub includes a pair offingers positioned to lie on opposite side of the drive post in spacedapart relation therewith, the interior wall includes a pair of ribs, andthe fingers engage the ribs and snap over the ribs during movement ofthe removal hub between locking and releasing positions.
 36. A lockablefuel cap for mounting in an open end of a vehicle filler neck, the fuelcap comprisinga closure member adapted to mate with the open end of thevehicle filler neck, the closure member being formed to include aninterior region and having a drive tooth positioned to lie in theinterior region, a removal hub positioned to lie in the interior regionof the closure member and being formed to include a drive lug and adrive post, the removal hub being movable between a locking position inwhich the drive lug is spaced apart from the drive tooth and a releasingposition in which the drive lug engages the drive tooth, an outer shellincluding an interior wall being configured to guide the movement of theremoval hub between the locking and releasing positions, the outer shellbeing rotatable relative to the closure member and drivingly coupled tothe removal hub so that the closure member remains stationary uponrotation of the outer shell in cap-removal direction when the drive lugis in the locking position and the closure member rotates in thecap-removal direction upon rotation of the outer shell in thecap-removal direction when the drive lug is in the releasing position, alock cylinder rotatable relative to the outer shell, the lock cylinderincluding a throw member being positioned to engage the drive-post ofthe removal hub during rotation of the lock cylinder to move the removalhub from the locking position to the releasing position, and aninstallation hub drivingly coupled to the outer shell to transmitrotation of the outer shell in a cap-installation direction to theclosure so that rotation of the outer shell in the cap-installingdirection allows the fuel cap to be installed in the filler neck. 37.The fuel cap of claim 36, wherein the removal hub includes arcuate frontand rear walls defining an inner region therebetween, and also whereinthe drive post lies within the inner region and the drive lug is formedto extend away from the front wall.
 38. The fuel cap of claim 37,wherein the interior wall of the outer shell includes a pair of ribs andthe removal hub includes a pair of fingers appended to one of thearcuate front and rear walls such that each finger moves across arespective rib during movement of the removal hub between locking andreleasing positions.
 39. The fuel cap of claim 38, wherein the fingersare flexible and deflect away from the interior wall of the outer shellupon movement of the fingers across each respective rib.
 40. The fuelcap of claim 36, wherein the interior wall includes a guide slot and theremoval hub includes a guide lug received within the guide slot forsliding movement relative to the interior wall.
 41. The fuel cap ofclaim 40, wherein the interior wall is further formed to include a boreand a portion of the drive post is positioned to lie in the bore. 42.The fuel cap of claim 40, wherein the interior wall includes a secondguide slot and the removal hub includes a second guide lug extendinginto the inner region and being received by the interior wall forsliding movement relative to the interior wall as the removal hub ismoved between locking and releasing positions.
 43. The fuel cap of claim42, wherein the drive post of the removal hub is positioned to liebetween the first and second guide lugs.
 44. The fuel cap of claim 36,wherein the outer shell includes a top plate positioned to lie outsidethe interior region of the closure member and an outer wall appended tothe to the top plate and extending over the closure member.
 45. The fuelcap of claim 44, wherein the outer wall includes a first bottom edgespaced a first distance from the top plate and the interior wallincludes a second bottom edge spaced a second distance from the topplate and the first distance is substantially equal to the seconddistance.
 46. The fuel cap of claim 36, wherein the fuel cap furtherincludes an installation hub comprising a ring and a driven portionextending upwardly from the ring, the outer shell including a cavitysuch that the driven portion is received within the cavity.
 47. The fuelcap of claim 46, wherein the fuel cap further includes a torque-overridering drivingly coupled to the installation hub and closure member suchthat rotational movement of the outer shell in a cap-installationdirection is transferred from the outer shell to the installation hub,to the torque-override ring, and finally to the closure member.